DIY multicooker repair, which will save you more than 1000 rubles

  • Dec 14, 2020

A multicooker is not a very expensive electrical appliance, but buying a new one can significantly reduce the family budget.

In this regard, it would not be superfluous to know the basic methods of diagnosing breakdowns of multicooker and a simple way to eliminate them.

Most often, serious breakdowns requiring replacement of the heater are extremely rare. The rest of the problems with work in 90% of cases can be eliminated by a person who is not prepared, while saving from 1000 rubles, which can be ripped off by "masters".

Consider an example of repairing a multicooker MIRTA
Consider an example of repairing a multicooker MIRTA

You just need to follow the instructions from the article and follow safety precautions. Namely, disconnect the voltage from the device at the moments when you touch it and manipulate its components.

For repair, you may need the following tools:

  • screwdriver;
  • multimeter or voltage indicator;
  • soldering iron;
  • tin and rosin;

If something is not in home tools, you can borrow it from friends for a while.

I had a MIRTA multicooker for repairs. An inexpensive popular device, which is in no way inferior to more expensive models in design and equipment.

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This multicooker has faithfully worked for more than two years and stopped heating.

At the same time, all other functions work perfectly, namely: the digital indicator lights up, the buttons are pressed, the menu is set, the mode starts, the time is counted, but no heating occurs.

All functions work, but the multicooker does not heat

To find out the cause of the malfunction, the microwave must be disassembled (scroll further the gallery with the description).

The first step is to remove the plastic pallet. This action is done in almost all multicooker of this form.
The first step is to remove the plastic pallet. This action is done in almost all multicooker of this form.
The first step is to remove the plastic pallet. This action is done in almost all multicooker of this form.
The first step is to remove the plastic pallet. This action is done in almost all multicooker of this form.
The first step is to remove the plastic pallet. This action is done in almost all multicooker of this form.
The first step is to remove the plastic pallet. This action is done in almost all multicooker of this form.

Usually a thermal fuse is installed at the entrance to the device, which is no longer here. A terminal is installed instead. Most likely, the multicooker has already been repaired, namely, the burned-out thermal fuse has been removed.

It is this thermal fuse that most often fails first. But in this case, the screen will not glow and the device will not give any signs of life at all.

Since it is not here, the second thing to check is the heating element.

To do this, it is enough to unscrew one of the wires from the heater so that the circuit does not change the readings of the device in any way. Although this is not necessary. The terminal is not removed in the photo.

You can check the heating element with any continuity of the circuit, be it a multimeter or an ohmmeter.

In this case, a multimeter was used, which must be put in the resistance measurement mode up to 200 Ohms.

We attach its ends to the conclusions of the heating element. The device showed a resistance of about 50 ohms and this indicates the integrity of the heater.

You can also check the resistance of the heating element to the case. Since the multicooker has metal body parts, with poor insulation of the heater, a dangerous potential may be present on its body.

To eliminate this, we connect one end of the probe to any output of the heating element, and the other to its metal case.

In this case, the multimeter must be set to measure the resistance of several megohms, that is, to the maximum.

With good insulation, the device should not show any resistance or show more than 1 megohm.

In the case when the resistance is low (several kOhm or Ohm), in no case should you use a multicooker with such a heating element.

So, we checked the heater, we look for the malfunction further.
We check the thermal resistance. One of them is located on the top of the lid, the other under the heater, exactly in the center in a special container.

The leads from this thermistor are yellow and connected through a connector to the power board. To check this resistance, you need to disconnect the connector from the board. This will prevent the board elements from changing the readings of the device.
The leads from this thermistor are yellow and connected through a connector to the power board. To check this resistance, you need to disconnect the connector from the board. This will prevent the board elements from changing the readings of the device.
The leads from this thermistor are yellow and connected through a connector to the power board. To check this resistance, you need to disconnect the connector from the board. This will prevent the board elements from changing the readings of the device.

Now let's move on to measuring the resistor on the cover.

From it, two wires also go to the board and they are red.

We remove this connector and measure the resistance according to the method described above.
We remove this connector and measure the resistance according to the method described above.

So the problem is not in the thermistors.

You need to look for the problem in the power board. Therefore, for convenience, it must be removed.

It is fastened with two screws on the sides.

Unscrew them carefully with a Phillips screwdriver.
Unscrew them carefully with a Phillips screwdriver.
Unscrew them carefully with a Phillips screwdriver.

As soon as the control board gives a signal to stop heating, the contacts open and the voltage on the red wire disappears.

Further verification algorithm is as follows:

  1. check if the mains voltage comes to the board;
  2. whether voltage within 12V is supplied to the relay coil from the control board. In this case, the power contacts of the relay are closed and the mains voltage is supplied to the heating element;
  3. whether the mains voltage passes with closed contacts on the heating element.

Next, scroll through the step by step gallery!

If you haven't disconnected one wire from the heater yet, then it is time to do it. Better to disconnect the red wire.
If you haven't disconnected one wire from the heater yet, then it is time to do it. Better to disconnect the red wire.
If you haven't disconnected one wire from the heater yet, then it is time to do it. Better to disconnect the red wire.
If you haven't disconnected one wire from the heater yet, then it is time to do it. Better to disconnect the red wire.

Next, we measure the voltage at the terminals of the relay coil. We switch the device to measure DC voltage up to 20V. We connect the ends of the device to the soldering points of the relay outputs.

The multimeter shows 13.8V, which indicates the correct operation of the control board and the key, in the form of a transistor on the power board. Although there is voltage on the coil, there was no characteristic click.

But you still need a measurement, according to the third item on the list. That is, take measurements at the relay input.

Again, we put the switch on the measurement of alternating voltage and connecting one terminal of the device with the black wire, and the second with the red one - we look at the result.
Again, we put the switch on the measurement of alternating voltage and connecting one terminal of the device with the black wire, and the second with the red one - we look at the result.

The device showed zero voltage. Although, right there, when the probes were shifted to the board tracks, the readings were 13V.

It was clear that the problem was in the soldering, and only by looking at the joint through a magnifying glass, it was possible to see a microcrack around the coil lead.

Soldering this conclusion, the problem was immediately eliminated.

The relay worked clearly without bouncing and other problems.

Now it remains to put everything in place and assemble the multicooker body.

For a final check, pour some water into the bowl. After turning on the device and selecting the mode, turn on the start button.

You can see how the water gains temperature and the cooking time decreases. After a while, the water boiled. The sensors worked, periodically turning off the heating.
Thus, a successful repair of the multicooker was made.
Overheating, moisture corrosion or vibration of the device could be the cause of such a crack in the soldering.

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I also repaired a multicooker from another brand - detailed instructions on my website: https://www.asutpp.ru/remont-multivarki-svoimi-rukami.html